Illinois Attorney General Lisa Madigan and Will County State's Attorney Jim Glasgow have filed a joint lawsuit and are seeking a preliminary injunction against ExxonMobil for an Oct. 19 incident in which the company's refinery released oil in its surrounding area in Channahon Township.

Scott Mulford, Madigan's spokesman, said the lawsuit was filed jointly Wednesday on the basis of potential environmental outcomes.

"The severity of the situation and the allegations of environmental harm that the release of the substance caused was obviously one of the guiding factors in bringing the lawsuit," he said.

According to a press release from the Attorney General's office, the complaint alleges that the oil release occurred as a result of procedural failures at the site's coker unit, which released the oil into the air and fell on homes and farms within a four-mile radius of the refinery.

The refinery is located at Interstate 55 and Arsenal Road. According to the release, Arsenal Road was closed because of slick conditions caused by the oil mixture settling into the road, and oil residue was detected in nearby Jackson Creek and along the Union Pacific Railroad tracks.

The preliminary injunction seeks to require the company to complete an investigation into the incident's cause within a week and to report the findings to the Illinois Environmental Protection Agency, submit a work schedule for necessary improvements, and report all pollutants and quantities involved in the oil release incident, the release said.

The injunction also seeks to require ExxonMobil to collect water samples in Jackson Creek and soil samples from the Arsenal Road area for analysis, provide equipment maintenance and inspection reports and provide a detailed explanation of the procedures used to restart the coker unit following Oct. 19.

“We’re seeking a comprehensive investigation of the cause of the oil release and development of a thorough cleanup plan to ensure that ExxonMobil is held accountable for the environmental impact caused by its refinery’s release of oil into the air and land,” Madigan said in the release.

Glasgow agreed.

“ExxonMobil must accept full responsibility for the harm this oily mist caused our environment as well as the farms, houses, vehicles, streets and other personal and public property in our surrounding communities,” he said. “The preliminary injunction we seek in cooperation with Attorney General Madigan ensures that this incident will be thoroughly investigated and that ExxonMobil will clean up damaged properties and natural resources.”

Mulford added that the response to the situation will require serious work on ExxonMobil's behalf going forward.

"It was a serious situation — the county State's Attorney and our office allege environmental harm was done and steps need to be taken to mitigate any problems associated with the incident," he said.

Tricia Simpson, Midwest public and government affairs manager for ExxonMobil Joliet Refinery, provided prepared remarks to the Morris Daily Herald.

"The ExxonMobil Joliet Refinery deeply regrets the release on October 19, 2012, and we apologize to those who were inconvenienced," the remarks said. "ExxonMobil has worked closely with local, state and federal officials from the outset on the initial response, recovery and investigation. The incident is under investigation in cooperation with state and federal regulators. ExxonMobil fully concurs with the requirements in the Attorney General's Agreed Interim Order, most of which were identified and voluntarily initiated in the 12 days since the incident."

A status hearing for the case will take place at 9 a.m. Friday, Nov. 2 in Joliet. Supervising Attorney Rebecca Burlingham and Assistant Attorney General Robert Petti are handling the case for Madigan’s Environmental Enforcement Bureau.